Python detects if the string contains characters in a character set

This article mainly describes whether the python detection string contains characters in a character set, the need for friends can refer to the following

Objective

Detects whether characters in a character set are included in a string

Method

The most concise method is the following, clear, universal, fast, applicable to any sequence and container

The code is as follows:

def containany (Seq,aset):

For C in SEQ:

If C in Aset:

Return True

Return False

The second application of the Itertools module to improve performance is essentially the same method as the former (although this approach violates Python's core view: simplicity, clarity)

Description of Itertools.ifilter (predicate, iterable)

Make a iterator that filters elements to iterable returning only those to which the predicate is True. IF predicate is None, return the items that are true.

For example:

IFilter (Lambda x:x%2, Range ())--> 1 3 5 7 9

The code is as follows:

Import Itertools

def containany (Seq,aset):

For item in Itertools.ifilter (ASET.__CONTAIN__,SEQ):

Return True

Return False

If you want to detect whether two strings are included, you must check all the subkeys, preferably the set type, where set (Aset). Difference (seq) is an element that is present in aset but not in seq:

The code is as follows:

def containall (Seq,aset):

Return not set (Aset). difference (seq)

For example, the following example:

The code is as follows:

In [4]: l1=[1,2,3,4]

In [5]: l2=[1,4,3,1]

In [6]: Containall (L1,L2)

OUT[6]: True

In [7]: Containall (L2,L1)

OUT[7]: False

Note that set.symmetric_difference refers to elements unique to two collections

The code is as follows:

In [9]: l2=[3,2,4,5]

In [ten]: X=set (L1)

In [one]: x.symmetric_difference (L2)

OUT[11]: Set ([1, 5])